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160 Cards in this Set

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Sellar mass
Pituitary macroadenoma
Craniopharyngioma
Rathe’s cleft cyst
Rathke’s cleft cyst
arises from failure of obliteration of the lumen of Rathke’s pouch, which develops as a rostral outpouching of the primitive oral cavity; Rathke’s pouch has an anterior and posterior portion and a central embryonic cleft; - anterior wall becomes the anterior lobe of the pituitary gland and the pars tuberalis; the posterior wall becomes the pars intermedia; residual lumen of the pouch is reduced to a narrow Rathke’s cleft which generally regresses. It’s persistence and enlargement is said to be the cause of the symptomatic Rathke’s cleft cyst.

· MRI: cystic intrasellar mass with extension into the suprasellar region and usually (two-thirds) T1-bright signal intensity and variable T2-intensity.

· Ddx: cystic craniopharyngiomas or cystic pituitary adenomas; enhancement of the wall in a cystic neoplasm may help differentiate neoplasms from non-neoplastic cysts. (Craniopharyngioma will enhance.)

· small and asymptomatic; may present with HA(most common), visual disturbance, hypopituitarism or diabetes insipidus.

· Tx: cyst aspiration and partial removal
Suprasellar mass
SATCHMOE
Sellar lesion- adenoma
Aneurysm, Arachnoid cyst
Teratoma- germinoma, dermoid, epidermoid
Cranipharyngioma
Hypothalamic glioma, hamartoma of tuber cinerium
Meningioma
Mets
Optic glioma- NF
EG
Ddx: infundibular thickening adult – sarcoid, TB, meningitis, mets, glioma, lymphoma, germinoma, lymphocytic hypophysitis (preg women), choristoma: peds - EG, suprasellar germinoma (Diabetes inspidus)
(ectopic pituitary, no stalk, ped)
(Rathke’s cleft cyst- sellar, variable signal)
Pituitary apoplexy
massive hem into pit adeoma (bromocriptine), necrosis, or infarct
Sheehan- post partum infarct of ant pit
Hetero signal, hi T1
Intraventricular tumors- adults
glioma- astro, incl giant cell c TS- calc, subependymoma, oligo,
meningioma- trigone, follows GM signal- rel low T2
mets
cysticercosis- V3
central neurocytoma- septum (arise/abutt)
colloid cyst – V3
Lesion near foramen monro
colloid cyst- variable signal, typical hi T1/low T2
giant cell astrocytoma- TS
cysticercosis
Intraventricular tumors- kids
ependymoma- V4 (supratent- NOT intravent)
choroid plexus papilloma- trigone>V3
pnet
teratoma
astrocytoma
eg of stalk
(xanthogranuloma- lat, older, usu bilat, large, calc, fat, cyst)
Third ventricle (V3) mass
Colloid cyst
Glioma (giant cell astrocytoma)
Meningioma
Choroid plexus papilloma-frondy
Aneurysm
Pineal lesions
Craniopharyngioma- adults
(Cystic- arahnoid cyst, ependymal cyst, cysticerc)
Choroid plexus papilloma
most <2y, M>>F
trigone (kids)> V4 (adults)
large, smooth lobulated, calcs, engilf glomus of c.p., fronds
vent dil- CSF overproduction
intense homo enhancement
Post fossa mass- peds
Medulloblastoma: (M>f, vermis c extension to 4th vent c edema- displ and efface v4, necrosis or cystic change in up to 50%, ca 20%, heme rare, CT: solid, HYPER, MR: hypo t1, variable t2, intense enhancement
csf seeding common & systemic (5%) mets
Astrocytoma (Juvenile pilocytic astrocytoma): (Inc freq in NF, can, occur optic & cerebrum, most @ vermis, can extend to cerebellar hem
cystic c mural nodule or solid, CT: iso or hypo, MR: iso/hypo t1, hyper t2, nodule intensely enhance, vs hemangioblastoma (adult))
Ependymoma: (usu 4th vent, can be supratent (parench), 30% - 50% calcify, **extension thru foramen of Luschka into cp °, thru Magendie to cisterna magna & foramen magnum, high recurrence, ct: hetero iso calcs and hem much more common than med and expand rather than displ)
Brainstem glioma: (peak: 3-10, high recur, poor px, usu anaplastic, GBM, RT, *exophytic growth to adjacent cisterns, *pontine enlargement (pons extends beyond basilar a), *alteration of 4th vent contour
Choroid plexus papilloma
Pineal region masses
Germ cell tumors (60%)
germinoma: m>>f- dense on CT, calcs
teratoma- fat
embryonal carcinoma
endodermal sinus tumor
choriocarcinoma- bleed
Pineal parenchymal (14%)
Pineocytoma
Pineoblastoma - PNET highly malig (also c trilateral retinoblastoma)
other
pineal cyst
glioma
meningioma (tentorial)
vein of Galen aneurysm
arachnoid cyst
lipoma
Supratentorial cystic mass c enhancing nodule
Pleomorphic xanthoastrocytoma
Ganglioglioma/gangliocytoma- young adults
Desmoplastic infantile ganglioglioma (DIG)- infant, most F and P, sz, enlarging head, nodule superficial
Large tumors, superficial, no sig edema, seizures
DNET (dysembryoplastic neuroepithelial tumor)
gr 1, always presents c seizures
Cortical, often TL
no edema, calc, enhance, well def
multicystic
megagyric- can remodel bone- LA, hi T2, nl wm thru lesion, like thick ctx
cortical dysplasia
developmental lesion?
Extra-axial lesion (neuro - brain)
Mets to bone
Meningioma- encase/narrow cav ICA typical
Hemangiopericytoma
Granulocytic sarcoma/chloroma- AML
Arachoid cyst
Epidermoid
Intracranial plasmacytoma- mimics meningioma
Bony lesion
Empyema
CNS lymphoma
AIDS
B-cell nNHLl
multifocal, well-demarcated enhancing (focal) lesions scattered in wm, periventricular
most supratent, can be central-thal
ca/hem rare
spread via cc
hypo t2, hyper ct
difficult to differentiate from toxo (usu @ g/w jxn & bg)
systemic dz involves leptomeninges
Ring enhancing lesions
MAGIC DR

Mets- SCC (cystic)
Abscess- infection, including TB*, toxo
Glioma
Infarct, resolving
Contusion
Demyelinating- tumefactive MS, ADEM, lyme
Radiation necrosis, resolving hematoma
Cavernous sinus lesion
(CN 3,4,5,6)

schwanoma
menigioma- encases/narows ica- typical
pituitary adenoma
lymphoma
aneurysm
chordoma
chondrosarcoma
infection
carotid-cavernous fistula
PICA infarct
dorsolateral medullary infarct – Wallenberg syndrome
ipsilateral facial pain/numbess
contralateral dec pain/temp
nystagmus/ataxia/diplopia
Venous infarction
due to SSST with propogation of clot into cortical veins
parasagittal
edema – cortical/subcortical WM
MR blood (timing and signal in stroke)
acute (7-72 hrs) - deoxy (intracell, para) - I , D
early subacute (4-7d)- met (ferric)- (intra) - B , D
late subacute (1-4w) - met (extra)- B, B
chronic (mos) - hemosiderin- D, D
hyperacute- oxyhb (diamagnetic, does not affect mr signal) - t1- iso, t2- bright
gradient echo- deoxy & hemosiderin- dark (and calc)
Intracranial hemorrhage/hematoma Ddx:
Aneurysm/AVM
Angiopathy (amyloid, vasculitis)
Tumor (primary – glioma); mets; melanoma, renal cell, chorioca, thyroid, common – lung, breast ; HIV – toxo, lymphoma
Hemorrhagic infarct
Hypertensive hemorrhage – bg, pons, cerebellum; can be secondary to COCAINE
Coagulopathy
Trauma
Ddx for abnormal FLAIR signal in SAH:
Blood
Carcinomatosis
Meningitis
Infarct
anesthesia
Cortical abnormal signal
Infarct – can be metabolic – i.e. MELAS
Glioma
Cerebritis/encephalitis
(demyelinating c WM)
Laminar necrosis
Ischemic changes affecting deep sensitive layers of ctx
Acute- linear hi T1, enhance, WM edema T2
Chronic- thin hpointense ctx?, big csf space
Global anoxia
Cortical infarct- CT and MR enhancement timing
Hyperacute <12 h
Dense MCA, loss ribbon
Edema

Acute- early (12-24h)
*Cortical arterial vessel enhancement- slow flow via collaterals
Subtle cortical low T1/hi T2
Loss G-W

Acute- late (1-7d)
Gyral enhancement- CT
*Intravscular enhancement- MR- vessels supplying infarct p 1-3 d
*Meningeal enhacement- mr

*Subacute (7-30d)
Less mass effect
Gyral blush and ring enhancement- Ct
*Gyriform parenchymal enhancement- mr

Chronic (>30d)
Atrophy, encephalomalacia, gliosis
Wallerian degeneration of corticospinal tracts
No enhancement
Dissection
Trauma
Fibrous dysplasia
Marfan’s/E-D
Cystic medial necrosis
Moyamoya
Occlusion of the supraclinoid ICA and proximal ACA, MCA, PCA of unknown etiology; prominent collaterals in BG from lenticulostriates and thalamoperfororators; dx of exclusion

o Ddx: sickle cell, RT, Meningioma, basal meningitis, NF1
Sickle Cell Disease in Neuro
infarction related to stasis and ischemia in the vasa vasorum, leading to intimal and medial hyperplasia with eventual significant narrowing or occlusion of the ICA or prox ACA and MCA. This can look like moyamoya with prominent collateral circulation
AVM
Enlarged feeding artery – have aneurysm along artery – due to high flow
Core /nidus – aneurysm here prone to rupture
Enlarged draining vein
Encephalomalacia may be present due to “steal” phenomenon
CT: vessels appear iso-hyperdense due to blood; calcification may be seen
MRI: serpentine flow voids
Tx: depends on size, location
Embo, Sx, radiation
Embo often staged; as AVM is occluded, avoid increased blood flow to ischemic brain which can become edematous and hemorrhage
15% are dural; 50% in PF – dural arterial flow; drains into sigmoid/transverse sinuses; etiology – venous thrombosis and development of collaterals with venous hypertension; if blood drains into cortical veins – at risk for venous infarction and/or intracranial hemorrhage (intraparechymal/SAH)
Abnormal signal deep gray
Degenerative
Metabolic
Toxic
Bilateral thalamic lesions (high T2)
Venous or arterial (basilar tip) infarct
Encephalitis
Glioma
Metabolic – anoxia, Wernike, Wilson, osmotic myelinolysis
BG Hi T1
Hypoxic-ischemic encephalopathy - neonates
liver failure
hyperpara & hypopara & pseudohypo
hyperalimentation
porto systemic shunt
depo of paramag ions- low on T2, globus pallidus- Krabbe’s dz
BG hi T2, symmetric
anoxia- CO, smoke inhalation, near drowning
Leigh’s dz- sporadic, lactic acidosis
Creutzfeldt-Jakob dz- caudate head and putamen
Hallervorden-Spatz dz- destruction of globus pallidus and substantia nigra- initial low T2 of globus pallidus then hi T2
Low T2 globus pallidus and thalami
never NL (iron depo)- nonspecific- neurodegenerative

Demyelinating (MS)
Leukodystrophy- Krabbe’s
Brain anoxia/infarct
Wilson’s
Hallervorden-Spatz
Metabolic
Sig head trauma
BG Calcs
in utero HIV
hyperpara & hypopara
tb, cysticercosis
CO- globus pallidus
Lead
Idio- senecent- g.p.
Fahr dz- familial cerebrovascular ferrocalcinosis- extensive bilat bg calc & dentate nuclei & wm- deep & subcortical
Leptomeningeal enhancement
Mets- primary CNS and non- PNET, med, lung, breast, lymphoma, melanoma
Meningitis- bact, TB, fungal, chemical –rupture dermoid
Sarcoid- also parenchymal and mimic meningioma
SAH, old
Post surgical
Leptomeningeal carcinomatosis
mimic meningitis
cranial nerve palsies, hcp (involve basal cisterns)
1° cns
adeno (breast, lung)
leukemia/lymphoma
Dural enhencement
Mets- prostate, breast, neuroblastoma (kid)
Lymphoma/leukemia
Child - neuroblastoma
Meningioma
Granulomatous- TB, sarcoid, Wegener’s
Spont iC hypotension – post LP
Post cranial sx
Chronic subdural hematoma
Idiopathic hypertrophic pachymeningitis
Enhancing ventricular margins
Subependymal mets- lung, breast, melanoma
Sub/ependymal seeding of CNS primary- med, glioma, epen
Lymphoma
Inflammatory ventriculitis
WM abnormality
MS- Marburg (acute, younger, fever, rapid,extensive), Devic (optic neuritis and cord), tumefactive
ADEM- Hursts (acute hemorrhagic leukoencephalitis), viral, vax. monophasic
PML
SSPE?
Vasculitis
Migraine
Lyme
Leukodystrophy
CADASIL- Cerebral Aut Dom Arteriopathy c Subcortical Infarcts & Leukoencephalopathy
MVID
DAI
Diffuse necrotizing leukoencephalopathy- intrathecal MTX, RT
Transependymal CSF flow
Epidural and subdural abscess/empyema
(head)
Extension from sinusitis, frontal
Craniotomy
Meningitis
Epidural- thru midline but not sutures
Cx: cerebritis, abscess, venous sinus thrombosis
Basal meningitis (granulomatous)
TB
Sarcoidosis – likes cranial nerves – optic nerve
Fungal- crypto, candida, cocci, mucor, blasto, nocardia, actino
Cerebritis, abscess, HCP
Infections
HSV- med TEMPORAL, insula, limbic, usu uni, edema, hem, enhance, can be bi
HIV- atrophy, PV wm dz, often c CMV
Cysticercosis
parenchymal- sz, neuro def
intraventricular- obs hcp
subarachnoid- comm hcp
IM cord-rare
Cryptococcosis- gelatinous pseudocysts, meningitis
Abscess- thin wall cventral- rupture into vent, ventriculitis (ependymitis)
Limbic encephalitis
Paraneoplastic- small cell (also cerebellar degen), ovarian, GI, breast, Hodgink, NB
Autoimmune. AMS, memory impaired
Medial temporal lobes, hypothal, +/- mild enhance, usu bilat
Ddx: herpes, CO (c globus pallidus involvement)
Rhombencephalitis- LISTERIA
immunocomp, occupational (farm animals)
meningitis or enceph
predilection for BRAINSTEM & CEREBELLUM
may enhance
can cause abscess
ddx: tb, syphilis, sarcoid, ms, adem
SSPE (subacute sclerosing panencephalitis)
P measles, p 5 y
Slow, preogressive or rapid
PVWM, BG, cerebellum, brainstem
No enhancement, later-diffuse cortical atrophy
Holoprosencephaly- no septum pellucidum in all
Alobar- c severe facial anomalies, monoventricle, fused thal
Semilobar- intermediate- aprtial falx/fissure, partial occipital
Lobar- mild- unseparate frontal horns, falx may be present
Trisomies 13, 18
Hydranencephaly
Sec to in utero vascular insult- spared post fossa
alobar holoprosencephaly- no septum/fissure
bilat open lip schizencephaly- assoc c septo-optic dysplasia, interhem fissure preserved
maximal hydrocephalus- thinned but present mantle of cortex
NF
optic gliomas c extension to tracts
cerebral gliomas
UBO- brainstem, pons, BG, thal, cerebellum- can enhance, dysmyel?
*think of neurocut stuff in kids- nf, ts, s-w
NF2
bilat vestib schwannoma (or ther CN)
meningioma
ependymoma
Alexander’s dz
dysmyelinating. M, sporadic, big head, frontal to post
Dysmyelinating dz
Alexander’s- M, sporadic, big head, frontal to post
Canavan’s dz- jewish, AR, big head, occipital, extensive peripheral WM involvement*
Krabbe’s dz- dense thalami, corona, caudate body (low T2- paramagnetic)
Adrenoleukodystrphy- central occipital to periph and anterior, X
Metachromatic leukodystrophy- most common hereditary, AR, symmetric pvwm, atrophy
Leigh’s dz (subacute necrotizing ecephalopathy)- AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT)
Canavan’s dz
Dysmyelinating dz. jewish, AR, big head, occipital, extensive peripheral WM involvement*
Krabbe's dz
Dysmyelinating dz. dense thalami, corona, caudate body (low T2- paramagnetic)
Adrenoleukodystrophy
Dysmyelinating dz. central occipital to periph and anterior,5-10 yrs, x linked
symmetric, confluent posterior white matter, atrophy
peripheral rim enhancement- active
calcs unusual
long chain fatty acids
adrenal insufficiency
Metachromatic leukodystrophy
Dysmyelinating dz. most common hereditary, AR, symmetric pvwm, atrophy
Leigh's dz (subacute necrotizing encephalopathy)
Dysmyelinating dz. AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT)
Agnesis of corpus callosum
assoc c: (colpocephaly, bat wing, high riding V3, absent septum pellucidum)

HCP
Dandy-walker
Chiari II
Midline lipoma- interhem, suprasellar and quad cisterns, not true neoplasm
Holoprosencephaly
Porencephaly
Encephalocele
Can be isolated, Probst bundles, absent cingulate gyrus
Ant CC usu present c dysgenesis
Absence Of Septum Pellucidum
Holoprosencephaly
Septo-optic dysplasia- assoc c schizencephaly, absent olfactory bulbs
Callosal agenesis
Schizencephaly
Severe chronic hydrocephalus
Destructive porencephaly
Heterotopia
Migrational anomaly, sz
Subependymal, ant and post horns- iso to GM, no enhance
Band (laminar)- subcortical WM
Ddx: subependymal tumor spread, heme, vascular malform, TS, IV meningioma, NF
Rhombencephalosynapsis
fused cerebellum, dent nuclei, sup cerer peduncle, thal
absent vermis, v4 pointed post- keyhole
absent septum pellucidum
Gray matter heterotopia
Subependymal
Deep white matter
Band heterotopia- often symmetric
Sturge-Weber
facial vascular nevus in the territory of the ophthalmic division of the trigeminal nerve, seizures, dementia, hemiplegia, hemianopsia, and congenital glaucoma or buphthalmos
sporadic
characteristic leptomeningeal venous angioma (subarachnoid space) and facial nevus are most commonly unilateral, but may be bilateral
Intraparenchymal calcification, parenchymal volume loss, engorgement of deep veins, and leptomeningeal and choroid plexus angiomata*- calcify and hi T2
Cortical calcs: pericapillary distribution in the fourth layer of the atrophied cerebral cortex- may not see on MR- gre/T2 only
Mr: thickened ctx and dec convolutions- Atrophy
Assoc c ddm synd
Dyke davidoff mason
Ipsilateral hypertrophy of cranium secondary to cerebral hemiatrophy (compensatory thickening of inner table)
Enlarged orbits, sinuses, mastoids, thick ctx
Sec to vasc insult
Also c Sturge-Weber
J-shaped sella
CONMAN

Chronic hydrocephalus
Optic glioma, OI
neurofibromatosis
Mucopolysaccharidosis
Achonondroplasia
Normal variant
Basilar invagination
Chamberlain and McGregor’s line- dens>5 mm above- superior migration of dens thru foramen magnum
Compresses cord/brainstem
"PF ROACH"
Paget disease
Fibrous dysplasia
Rickets
Osteogenesis imperfecta, Osteomalacia
Achondroplasia
Cleidocranial dysplasia
Hyperparathyroidism, Hurler syndrome
Wernike’s encephalopathy
Bilat symmetric thalamic hi T2
Alcoholics and vomiting preg
Reversible c thiamine
Ddx: osmotic myelinolysis
Cerebellar atrophy
Generalized- c cerebral atrophy
Olivopontocerebellar degeneration- Friedreich ataxia
Ataxia-telangiectasia – AR, sinopulm infections, ICH, lymphoma/leukemia
EtOH- midline (vermis)
Dilantin
Paraneoplastic (usu small cell)
Radiation
Focal- trauma, infarct
Posterior reversible encephalopathy syndrome (PRES)
@ g-w jxn, ext capsule, bg, cortical & subcortical wm (OCCIPITAL)- neg DWI
sz, visual disturbance, obtundation, resolves w/in days
HTN-acute elev of BP as little as 10 mmHg
preeclampsia/eclampsia - htn, proteinuria, +sz/coma
Cyclosporine toxicity, OKT3- immunosup
Cocaine, heroin
Chemorx: MTX, cisplatin
CRF?
TTP, HUS?
SLE(rare)
Diffuse cerebral atrophy
Degenerative - Alzheimer’s, Pick, J-C dz- caudate head/putamen and cortical gyriform hi T2, no WM/gad
MS, encephalitis
Trauma
Radiation
Drugs- dilantin, steroids, MTX, pot, chemo, EtOH
HIV encephalopathy
Infarcts
Renal failure
Age
Anorexia
Dyke-davidoff-mason- unilat
Gyral enhacement
Meningeal carcinomatosis- breast, lung, melanoma, lymphoma
Primary cns tumor c seeding- medulloblastoma, pineoblastoma, ependymoma
Meningitis- any
Cerebritis- focal/encephalitis- diffuse, viral
SAH
Subacute infarct
Ventricular margin enhancement
Subependymal met extension- small cell, breast, melanoma
Subependymal seeding of CNS primary- glioma, ependymoma, medulloblastoma, germinoma
Lymphoma
Ventriculitis- rupture or from basal cisterns
Ventriculitis
Trauma
Absecess rupture
Bacteremia
Surgical (shunt)
Meningitis
Hiv- CMV, lymphoma
Diffuse axonal injury (DAI)
Locations
1. Lobar WM- F/T

2. CC- posterior

3. Brain stem- dorsolateral pons/mid

Shearing, petch hem later
Severe neuro deficit
Persistent trigeminal artery
up to 1/2%
hypoglossal & otic
assoc c avm & aneurysms
can course thru sella**
usu precavernous, can be intracavernous
prox basilar & distal vert & pcom can be hypoplastic
assoc c tic doloureux & vb insuff
Spontaneous intracranial hypotension
Postural HA
Iatrogenic (LP, surgery), spontaneous (rupture of Tarlov cyst), trauma, thoracic diverticula
Chronic, intermittent CSF leak
Low-lying tonsils, elongated V4, bilat dubdural effusion, dural enhancement
CNS vasculitis
infect- tb, syphilis
non-infect
Primary angiitis
PAN
Sarcoid
wegener's
coll-vasc- SLE, RA
antiphospholipid ab- ischemia
drugs- amph, x, coke


primary (isolated) angiitis of the CNS (PACNS)
no systemic vasculitis
*systemic c CNS involvement
Churg-Strauss
PAN** (most cmmn to affect CNS)
Microscopic polyangiitis (lung and kids)
Wegener's
Behcet's dz- nonspec, BG, brainstem, WM
giant cell arteritis
SLE usu stroke
antiphospholipid
ra, scleroderma, sjogren's
Lhermitte-duclos
posterior fossa dysplasia, mimicking a space-occupying lesion; aka - dysplastic gangliocytoma of the cerebellum and is considered a complex hamartoma; may occupy an entire cerebellar hemisphere; macroscopically the cerebellar folia appear hyperplastic. CT may be misleading since it shows a poorly delineated iso- or hypointense posterior fossa lesion without enhancement but with deformity of the fourth ventricle associated sometimes to hydrocephalus, that may mimic a posterior fossa neoplasm. MR shows a characteristic T2 pattern of laminated increased signal – like “tiger stripes”
MELAS
(mitochondrial encephalopathy, lactic acidosis and stroke)- infarcts not confined by vascular territory, spares WM, hits cortex where there is high metabolic activity, familial
MERRF
myoclonus, epilepsy, ragged red fibers)- adults
Sellar mass
Pituitary macroadenoma
Craniopharyngioma
Rathe’s cleft cyst
Rathke’s cleft cyst
arises from failure of obliteration of the lumen of Rathke’s pouch, which develops as a rostral outpouching of the primitive oral cavity; Rathke’s pouch has an anterior and posterior portion and a central embryonic cleft; - anterior wall becomes the anterior lobe of the pituitary gland and the pars tuberalis; the posterior wall becomes the pars intermedia; residual lumen of the pouch is reduced to a narrow Rathke’s cleft which generally regresses. It’s persistence and enlargement is said to be the cause of the symptomatic Rathke’s cleft cyst.

· MRI: cystic intrasellar mass with extension into the suprasellar region and usually (two-thirds) T1-bright signal intensity and variable T2-intensity.

· Ddx: cystic craniopharyngiomas or cystic pituitary adenomas; enhancement of the wall in a cystic neoplasm may help differentiate neoplasms from non-neoplastic cysts. (Craniopharyngioma will enhance.)

· small and asymptomatic; may present with HA(most common), visual disturbance, hypopituitarism or diabetes insipidus.

· Tx: cyst aspiration and partial removal
Suprasellar mass
SATCHMOE
Sellar lesion- adenoma
Aneurysm, Arachnoid cyst
Teratoma- germinoma, dermoid, epidermoid
Cranipharyngioma
Hypothalamic glioma, hamartoma of tuber cinerium
Meningioma
Mets
Optic glioma- NF
EG
Ddx: infundibular thickening adult – sarcoid, TB, meningitis, mets, glioma, lymphoma, germinoma, lymphocytic hypophysitis (preg women), choristoma: peds - EG, suprasellar germinoma (Diabetes inspidus)
(ectopic pituitary, no stalk, ped)
(Rathke’s cleft cyst- sellar, variable signal)
Pituitary apoplexy
massive hem into pit adeoma (bromocriptine), necrosis, or infarct
Sheehan- post partum infarct of ant pit
Hetero signal, hi T1
Intraventricular tumors- adults
glioma- astro, incl giant cell c TS- calc, subependymoma, oligo,
meningioma- trigone, follows GM signal- rel low T2
mets
cysticercosis- V3
central neurocytoma- septum (arise/abutt)
colloid cyst – V3
Lesion near foramen monro
colloid cyst- variable signal, typical hi T1/low T2
giant cell astrocytoma- TS
cysticercosis
Intraventricular tumors- kids
ependymoma- V4 (supratent- NOT intravent)
choroid plexus papilloma- trigone>V3
pnet
teratoma
astrocytoma
eg of stalk
(xanthogranuloma- lat, older, usu bilat, large, calc, fat, cyst)
Third ventricle (V3) mass
Colloid cyst
Glioma (giant cell astrocytoma)
Meningioma
Choroid plexus papilloma-frondy
Aneurysm
Pineal lesions
Craniopharyngioma- adults
(Cystic- arahnoid cyst, ependymal cyst, cysticerc)
Choroid plexus papilloma
most <2y, M>>F
trigone (kids)> V4 (adults)
large, smooth lobulated, calcs, engilf glomus of c.p., fronds
vent dil- CSF overproduction
intense homo enhancement
Post fossa mass- peds
Medulloblastoma: (M>f, vermis c extension to 4th vent c edema- displ and efface v4, necrosis or cystic change in up to 50%, ca 20%, heme rare, CT: solid, HYPER, MR: hypo t1, variable t2, intense enhancement
csf seeding common & systemic (5%) mets
Astrocytoma (Juvenile pilocytic astrocytoma): (Inc freq in NF, can, occur optic & cerebrum, most @ vermis, can extend to cerebellar hem
cystic c mural nodule or solid, CT: iso or hypo, MR: iso/hypo t1, hyper t2, nodule intensely enhance, vs hemangioblastoma (adult))
Ependymoma: (usu 4th vent, can be supratent (parench), 30% - 50% calcify, **extension thru foramen of Luschka into cp °, thru Magendie to cisterna magna & foramen magnum, high recurrence, ct: hetero iso calcs and hem much more common than med and expand rather than displ)
Brainstem glioma: (peak: 3-10, high recur, poor px, usu anaplastic, GBM, RT, *exophytic growth to adjacent cisterns, *pontine enlargement (pons extends beyond basilar a), *alteration of 4th vent contour
Choroid plexus papilloma
Pineal region masses
Germ cell tumors (60%)
germinoma: m>>f- dense on CT, calcs
teratoma- fat
embryonal carcinoma
endodermal sinus tumor
choriocarcinoma- bleed
Pineal parenchymal (14%)
Pineocytoma
Pineoblastoma - PNET highly malig (also c trilateral retinoblastoma)
other
pineal cyst
glioma
meningioma (tentorial)
vein of Galen aneurysm
arachnoid cyst
lipoma
Supratentorial cystic mass c enhancing nodule
Pleomorphic xanthoastrocytoma
Ganglioglioma/gangliocytoma- young adults
Desmoplastic infantile ganglioglioma (DIG)- infant, most F and P, sz, enlarging head, nodule superficial
Large tumors, superficial, no sig edema, seizures
DNET (dysembryoplastic neuroepithelial tumor)
gr 1, always presents c seizures
Cortical, often TL
no edema, calc, enhance, well def
multicystic
megagyric- can remodel bone- LA, hi T2, nl wm thru lesion, like thick ctx
cortical dysplasia
developmental lesion?
Extra-axial lesion (neuro - brain)
Mets to bone
Meningioma- encase/narrow cav ICA typical
Hemangiopericytoma
Granulocytic sarcoma/chloroma- AML
Arachoid cyst
Epidermoid
Intracranial plasmacytoma- mimics meningioma
Bony lesion
Empyema
CNS lymphoma
AIDS
B-cell nNHLl
multifocal, well-demarcated enhancing (focal) lesions scattered in wm, periventricular
most supratent, can be central-thal
ca/hem rare
spread via cc
hypo t2, hyper ct
difficult to differentiate from toxo (usu @ g/w jxn & bg)
systemic dz involves leptomeninges
Ring enhancing lesions
MAGIC DR

Mets- SCC (cystic)
Abscess- infection, including TB*, toxo
Glioma
Infarct, resolving
Contusion
Demyelinating- tumefactive MS, ADEM, lyme
Radiation necrosis, resolving hematoma
Cavernous sinus lesion
(CN 3,4,5,6)

schwanoma
menigioma- encases/narows ica- typical
pituitary adenoma
lymphoma
aneurysm
chordoma
chondrosarcoma
infection
carotid-cavernous fistula
PICA infarct
dorsolateral medullary infarct – Wallenberg syndrome
ipsilateral facial pain/numbess
contralateral dec pain/temp
nystagmus/ataxia/diplopia
Venous infarction
due to SSST with propogation of clot into cortical veins
parasagittal
edema – cortical/subcortical WM
MR blood (timing and signal in stroke)
acute (7-72 hrs) - deoxy (intracell, para) - I , D
early subacute (4-7d)- met (ferric)- (intra) - B , D
late subacute (1-4w) - met (extra)- B, B
chronic (mos) - hemosiderin- D, D
hyperacute- oxyhb (diamagnetic, does not affect mr signal) - t1- iso, t2- bright
gradient echo- deoxy & hemosiderin- dark (and calc)
Intracranial hemorrhage/hematoma Ddx:
Aneurysm/AVM
Angiopathy (amyloid, vasculitis)
Tumor (primary – glioma); mets; melanoma, renal cell, chorioca, thyroid, common – lung, breast ; HIV – toxo, lymphoma
Hemorrhagic infarct
Hypertensive hemorrhage – bg, pons, cerebellum; can be secondary to COCAINE
Coagulopathy
Trauma
Ddx for abnormal FLAIR signal in SAH:
Blood
Carcinomatosis
Meningitis
Infarct
anesthesia
Cortical abnormal signal
Infarct – can be metabolic – i.e. MELAS
Glioma
Cerebritis/encephalitis
(demyelinating c WM)
Laminar necrosis
Ischemic changes affecting deep sensitive layers of ctx
Acute- linear hi T1, enhance, WM edema T2
Chronic- thin hpointense ctx?, big csf space
Global anoxia
Cortical infarct- CT and MR enhancement timing
Hyperacute <12 h
Dense MCA, loss ribbon
Edema

Acute- early (12-24h)
*Cortical arterial vessel enhancement- slow flow via collaterals
Subtle cortical low T1/hi T2
Loss G-W

Acute- late (1-7d)
Gyral enhancement- CT
*Intravscular enhancement- MR- vessels supplying infarct p 1-3 d
*Meningeal enhacement- mr

*Subacute (7-30d)
Less mass effect
Gyral blush and ring enhancement- Ct
*Gyriform parenchymal enhancement- mr

Chronic (>30d)
Atrophy, encephalomalacia, gliosis
Wallerian degeneration of corticospinal tracts
No enhancement
Dissection
Trauma
Fibrous dysplasia
Marfan’s/E-D
Cystic medial necrosis
Moyamoya
Occlusion of the supraclinoid ICA and proximal ACA, MCA, PCA of unknown etiology; prominent collaterals in BG from lenticulostriates and thalamoperfororators; dx of exclusion

o Ddx: sickle cell, RT, Meningioma, basal meningitis, NF1
Sickle Cell Disease in Neuro
infarction related to stasis and ischemia in the vasa vasorum, leading to intimal and medial hyperplasia with eventual significant narrowing or occlusion of the ICA or prox ACA and MCA. This can look like moyamoya with prominent collateral circulation
AVM
Enlarged feeding artery – have aneurysm along artery – due to high flow
Core /nidus – aneurysm here prone to rupture
Enlarged draining vein
Encephalomalacia may be present due to “steal” phenomenon
CT: vessels appear iso-hyperdense due to blood; calcification may be seen
MRI: serpentine flow voids
Tx: depends on size, location
Embo, Sx, radiation
Embo often staged; as AVM is occluded, avoid increased blood flow to ischemic brain which can become edematous and hemorrhage
15% are dural; 50% in PF – dural arterial flow; drains into sigmoid/transverse sinuses; etiology – venous thrombosis and development of collaterals with venous hypertension; if blood drains into cortical veins – at risk for venous infarction and/or intracranial hemorrhage (intraparechymal/SAH)
Abnormal signal deep gray
Degenerative
Metabolic
Toxic
Bilateral thalamic lesions (high T2)
Venous or arterial (basilar tip) infarct
Encephalitis
Glioma
Metabolic – anoxia, Wernike, Wilson, osmotic myelinolysis
BG Hi T1
Hypoxic-ischemic encephalopathy - neonates
liver failure
hyperpara & hypopara & pseudohypo
hyperalimentation
porto systemic shunt
depo of paramag ions- low on T2, globus pallidus- Krabbe’s dz
BG hi T2, symmetric
anoxia- CO, smoke inhalation, near drowning
Leigh’s dz- sporadic, lactic acidosis
Creutzfeldt-Jakob dz- caudate head and putamen
Hallervorden-Spatz dz- destruction of globus pallidus and substantia nigra- initial low T2 of globus pallidus then hi T2
Low T2 globus pallidus and thalami
never NL (iron depo)- nonspecific- neurodegenerative

Demyelinating (MS)
Leukodystrophy- Krabbe’s
Brain anoxia/infarct
Wilson’s
Hallervorden-Spatz
Metabolic
Sig head trauma
BG Calcs
in utero HIV
hyperpara & hypopara
tb, cysticercosis
CO- globus pallidus
Lead
Idio- senecent- g.p.
Fahr dz- familial cerebrovascular ferrocalcinosis- extensive bilat bg calc & dentate nuclei & wm- deep & subcortical
Leptomeningeal enhancement
Mets- primary CNS and non- PNET, med, lung, breast, lymphoma, melanoma
Meningitis- bact, TB, fungal, chemical –rupture dermoid
Sarcoid- also parenchymal and mimic meningioma
SAH, old
Post surgical
Leptomeningeal carcinomatosis
mimic meningitis
cranial nerve palsies, hcp (involve basal cisterns)
1° cns
adeno (breast, lung)
leukemia/lymphoma
Dural enhencement
Mets- prostate, breast, neuroblastoma (kid)
Lymphoma/leukemia
Child - neuroblastoma
Meningioma
Granulomatous- TB, sarcoid, Wegener’s
Spont iC hypotension – post LP
Post cranial sx
Chronic subdural hematoma
Idiopathic hypertrophic pachymeningitis
Enhancing ventricular margins
Subependymal mets- lung, breast, melanoma
Sub/ependymal seeding of CNS primary- med, glioma, epen
Lymphoma
Inflammatory ventriculitis
WM abnormality
MS- Marburg (acute, younger, fever, rapid,extensive), Devic (optic neuritis and cord), tumefactive
ADEM- Hursts (acute hemorrhagic leukoencephalitis), viral, vax. monophasic
PML
SSPE?
Vasculitis
Migraine
Lyme
Leukodystrophy
CADASIL- Cerebral Aut Dom Arteriopathy c Subcortical Infarcts & Leukoencephalopathy
MVID
DAI
Diffuse necrotizing leukoencephalopathy- intrathecal MTX, RT
Transependymal CSF flow
Epidural and subdural abscess/empyema
(head)
Extension from sinusitis, frontal
Craniotomy
Meningitis
Epidural- thru midline but not sutures
Cx: cerebritis, abscess, venous sinus thrombosis
Basal meningitis (granulomatous)
TB
Sarcoidosis – likes cranial nerves – optic nerve
Fungal- crypto, candida, cocci, mucor, blasto, nocardia, actino
Cerebritis, abscess, HCP
Infections
HSV- med TEMPORAL, insula, limbic, usu uni, edema, hem, enhance, can be bi
HIV- atrophy, PV wm dz, often c CMV
Cysticercosis
parenchymal- sz, neuro def
intraventricular- obs hcp
subarachnoid- comm hcp
IM cord-rare
Cryptococcosis- gelatinous pseudocysts, meningitis
Abscess- thin wall cventral- rupture into vent, ventriculitis (ependymitis)
Limbic encephalitis
Paraneoplastic- small cell (also cerebellar degen), ovarian, GI, breast, Hodgink, NB
Autoimmune. AMS, memory impaired
Medial temporal lobes, hypothal, +/- mild enhance, usu bilat
Ddx: herpes, CO (c globus pallidus involvement)
Rhombencephalitis- LISTERIA
immunocomp, occupational (farm animals)
meningitis or enceph
predilection for BRAINSTEM & CEREBELLUM
may enhance
can cause abscess
ddx: tb, syphilis, sarcoid, ms, adem
SSPE (subacute sclerosing panencephalitis)
P measles, p 5 y
Slow, preogressive or rapid
PVWM, BG, cerebellum, brainstem
No enhancement, later-diffuse cortical atrophy
Holoprosencephaly- no septum pellucidum in all
Alobar- c severe facial anomalies, monoventricle, fused thal
Semilobar- intermediate- aprtial falx/fissure, partial occipital
Lobar- mild- unseparate frontal horns, falx may be present
Trisomies 13, 18
Hydranencephaly
Sec to in utero vascular insult- spared post fossa
alobar holoprosencephaly- no septum/fissure
bilat open lip schizencephaly- assoc c septo-optic dysplasia, interhem fissure preserved
maximal hydrocephalus- thinned but present mantle of cortex
NF
optic gliomas c extension to tracts
cerebral gliomas
UBO- brainstem, pons, BG, thal, cerebellum- can enhance, dysmyel?
*think of neurocut stuff in kids- nf, ts, s-w
NF2
bilat vestib schwannoma (or ther CN)
meningioma
ependymoma
Alexander’s dz
dysmyelinating. M, sporadic, big head, frontal to post
Dysmyelinating dz
Alexander’s- M, sporadic, big head, frontal to post
Canavan’s dz- jewish, AR, big head, occipital, extensive peripheral WM involvement*
Krabbe’s dz- dense thalami, corona, caudate body (low T2- paramagnetic)
Adrenoleukodystrphy- central occipital to periph and anterior, X
Metachromatic leukodystrophy- most common hereditary, AR, symmetric pvwm, atrophy
Leigh’s dz (subacute necrotizing ecephalopathy)- AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT)
Canavan’s dz
Dysmyelinating dz. jewish, AR, big head, occipital, extensive peripheral WM involvement*
Krabbe's dz
Dysmyelinating dz. dense thalami, corona, caudate body (low T2- paramagnetic)
Adrenoleukodystrophy
Dysmyelinating dz. central occipital to periph and anterior,5-10 yrs, x linked
symmetric, confluent posterior white matter, atrophy
peripheral rim enhancement- active
calcs unusual
long chain fatty acids
adrenal insufficiency
Metachromatic leukodystrophy
Dysmyelinating dz. most common hereditary, AR, symmetric pvwm, atrophy
Leigh's dz (subacute necrotizing encephalopathy)
Dysmyelinating dz. AR, GM necrosis- lowT1/hi T2- BG, thalami, substantia nigra, brain stem (lucent putamen on CT)
Agnesis of corpus callosum
assoc c: (colpocephaly, bat wing, high riding V3, absent septum pellucidum)

HCP
Dandy-walker
Chiari II
Midline lipoma- interhem, suprasellar and quad cisterns, not true neoplasm
Holoprosencephaly
Porencephaly
Encephalocele
Can be isolated, Probst bundles, absent cingulate gyrus
Ant CC usu present c dysgenesis
Absence Of Septum Pellucidum
Holoprosencephaly
Septo-optic dysplasia- assoc c schizencephaly, absent olfactory bulbs
Callosal agenesis
Schizencephaly
Severe chronic hydrocephalus
Destructive porencephaly
Heterotopia
Migrational anomaly, sz
Subependymal, ant and post horns- iso to GM, no enhance
Band (laminar)- subcortical WM
Ddx: subependymal tumor spread, heme, vascular malform, TS, IV meningioma, NF
Rhombencephalosynapsis
fused cerebellum, dent nuclei, sup cerer peduncle, thal
absent vermis, v4 pointed post- keyhole
absent septum pellucidum
Gray matter heterotopia
Subependymal
Deep white matter
Band heterotopia- often symmetric
Sturge-Weber
facial vascular nevus in the territory of the ophthalmic division of the trigeminal nerve, seizures, dementia, hemiplegia, hemianopsia, and congenital glaucoma or buphthalmos
sporadic
characteristic leptomeningeal venous angioma (subarachnoid space) and facial nevus are most commonly unilateral, but may be bilateral
Intraparenchymal calcification, parenchymal volume loss, engorgement of deep veins, and leptomeningeal and choroid plexus angiomata*- calcify and hi T2
Cortical calcs: pericapillary distribution in the fourth layer of the atrophied cerebral cortex- may not see on MR- gre/T2 only
Mr: thickened ctx and dec convolutions- Atrophy
Assoc c ddm synd
Dyke davidoff mason
Ipsilateral hypertrophy of cranium secondary to cerebral hemiatrophy (compensatory thickening of inner table)
Enlarged orbits, sinuses, mastoids, thick ctx
Sec to vasc insult
Also c Sturge-Weber
J-shaped sella
CONMAN

Chronic hydrocephalus
Optic glioma, OI
neurofibromatosis
Mucopolysaccharidosis
Achonondroplasia
Normal variant
Basilar invagination
Chamberlain and McGregor’s line- dens>5 mm above- superior migration of dens thru foramen magnum
Compresses cord/brainstem
"PF ROACH"
Paget disease
Fibrous dysplasia
Rickets
Osteogenesis imperfecta, Osteomalacia
Achondroplasia
Cleidocranial dysplasia
Hyperparathyroidism, Hurler syndrome
Wernike’s encephalopathy
Bilat symmetric thalamic hi T2
Alcoholics and vomiting preg
Reversible c thiamine
Ddx: osmotic myelinolysis
Cerebellar atrophy
Generalized- c cerebral atrophy
Olivopontocerebellar degeneration- Friedreich ataxia
Ataxia-telangiectasia – AR, sinopulm infections, ICH, lymphoma/leukemia
EtOH- midline (vermis)
Dilantin
Paraneoplastic (usu small cell)
Radiation
Focal- trauma, infarct
Posterior reversible encephalopathy syndrome (PRES)
@ g-w jxn, ext capsule, bg, cortical & subcortical wm (OCCIPITAL)- neg DWI
sz, visual disturbance, obtundation, resolves w/in days
HTN-acute elev of BP as little as 10 mmHg
preeclampsia/eclampsia - htn, proteinuria, +sz/coma
Cyclosporine toxicity, OKT3- immunosup
Cocaine, heroin
Chemorx: MTX, cisplatin
CRF?
TTP, HUS?
SLE(rare)
Diffuse cerebral atrophy
Degenerative - Alzheimer’s, Pick, J-C dz- caudate head/putamen and cortical gyriform hi T2, no WM/gad
MS, encephalitis
Trauma
Radiation
Drugs- dilantin, steroids, MTX, pot, chemo, EtOH
HIV encephalopathy
Infarcts
Renal failure
Age
Anorexia
Dyke-davidoff-mason- unilat
Gyral enhacement
Meningeal carcinomatosis- breast, lung, melanoma, lymphoma
Primary cns tumor c seeding- medulloblastoma, pineoblastoma, ependymoma
Meningitis- any
Cerebritis- focal/encephalitis- diffuse, viral
SAH
Subacute infarct
Ventricular margin enhancement
Subependymal met extension- small cell, breast, melanoma
Subependymal seeding of CNS primary- glioma, ependymoma, medulloblastoma, germinoma
Lymphoma
Ventriculitis- rupture or from basal cisterns
Ventriculitis
Trauma
Absecess rupture
Bacteremia
Surgical (shunt)
Meningitis
Hiv- CMV, lymphoma
Diffuse axonal injury (DAI)
Locations
1. Lobar WM- F/T

2. CC- posterior

3. Brain stem- dorsolateral pons/mid

Shearing, petch hem later
Severe neuro deficit
Persistent trigeminal artery
up to 1/2%
hypoglossal & otic
assoc c avm & aneurysms
can course thru sella**
usu precavernous, can be intracavernous
prox basilar & distal vert & pcom can be hypoplastic
assoc c tic doloureux & vb insuff
Spontaneous intracranial hypotension
Postural HA
Iatrogenic (LP, surgery), spontaneous (rupture of Tarlov cyst), trauma, thoracic diverticula
Chronic, intermittent CSF leak
Low-lying tonsils, elongated V4, bilat dubdural effusion, dural enhancement
CNS vasculitis
infect- tb, syphilis
non-infect
Primary angiitis
PAN
Sarcoid
wegener's
coll-vasc- SLE, RA
antiphospholipid ab- ischemia
drugs- amph, x, coke


primary (isolated) angiitis of the CNS (PACNS)
no systemic vasculitis
*systemic c CNS involvement
Churg-Strauss
PAN** (most cmmn to affect CNS)
Microscopic polyangiitis (lung and kids)
Wegener's
Behcet's dz- nonspec, BG, brainstem, WM
giant cell arteritis
SLE usu stroke
antiphospholipid
ra, scleroderma, sjogren's
Lhermitte-duclos
posterior fossa dysplasia, mimicking a space-occupying lesion; aka - dysplastic gangliocytoma of the cerebellum and is considered a complex hamartoma; may occupy an entire cerebellar hemisphere; macroscopically the cerebellar folia appear hyperplastic. CT may be misleading since it shows a poorly delineated iso- or hypointense posterior fossa lesion without enhancement but with deformity of the fourth ventricle associated sometimes to hydrocephalus, that may mimic a posterior fossa neoplasm. MR shows a characteristic T2 pattern of laminated increased signal – like “tiger stripes”
MELAS
(mitochondrial encephalopathy, lactic acidosis and stroke)- infarcts not confined by vascular territory, spares WM, hits cortex where there is high metabolic activity, familial
MERRF
myoclonus, epilepsy, ragged red fibers)- adults